<template>
  <el-table :data="formatData"
            :stripe="option.stripe"
            :row-style="showRow"
            :row-class-name="rowClassName"
            v-bind="$attrs"
            :border="border">
    <el-table-column v-if="columns.length===0"
                     width="150">
      <template slot-scope="scope">
        <span v-for="space in scope.row._level"
              class="ms-tree-space"
              :key="space"></span>
        <span class="tree-ctrl"
              v-if="iconShow(0,scope.row)"
              @click="toggleExpanded(scope.$index)">
          <i v-if="!scope.row._expanded"
             class="el-icon-plus"></i>
          <i v-else
             class="el-icon-minus"></i>
        </span>
        {{scope.$index}}
      </template>
    </el-table-column>
    <el-table-column v-else
                     :align="column.align"
                     v-for="(column, index) in columns"
                     :key="column.value"
                     :label="column.text"
                     :width="column.width">
      <template slot-scope="scope">
        <slot v-if="column.slotStatus" :name="column.value" :row="scope.row"></slot>
        <template v-else>
          <span v-if="index === 0"
                v-for="space in scope.row._level"
                class="ms-tree-space"
                :key="space"></span>
          <span class="tree-ctrl"
                v-if="iconShow(index,scope.row)"
                @click="toggleExpanded(scope.$index)">
            <i v-if="!scope.row._expanded"
              class="el-icon-plus"></i>
            <i v-else
              class="el-icon-minus"></i>
          </span>
          {{scope.row[column.value]}}
        </template>
      </template>
    </el-table-column>
    <slot></slot>
  </el-table>
</template>

<script>
import treeToArray from '@/util/eval'
export default {
  name: 'cvueTreeGrid',
  props: {
    option: {
      type: Object,
      required: true
    },
    rowClassName: Function,
    evalFunc: Function,
    evalArgs: Array
  },
  data () {
    return {}
  },
  created () {},
  computed: {
    data: function () {
      return this.option.data || []
    },
    columns: function () {
      return this.option.columns || []
    },
    expandAll: function () {
      return this.option.expandAll
    },
    border: function () {
      return this.option.border || true
    },
    // 格式化数据源
    formatData: function () {
      let tmp
      if (!Array.isArray(this.data)) {
        tmp = [this.data]
      } else {
        tmp = this.data
      }
      const func = this.evalFunc || treeToArray
      const args = this.evalArgs
        ? Array.concat([tmp, this.expandAll], this.evalArgs)
        : [tmp, this.expandAll]
      return func.apply(null, args)
    }
  },
  methods: {
    showRow: function (row) {
      const show = row.row.parent
        ? row.row.parent._expanded && row.row.parent._show
        : true
      row.row._show = show
      return show
        ? 'animation:treeTableShow 1s;-webkit-animation:treeTableShow 1s;'
        : 'display:none;'
    },
    // 切换下级是否展开
    toggleExpanded: function (trIndex) {
      const record = this.formatData[trIndex]
      record._expanded = !record._expanded
    },
    // 图标显示
    iconShow (index, record) {
      return index === 0 && record.children && record.children.length > 0
    }
  }
}
</script>
<style rel="stylesheet/css">
@keyframes treeTableShow {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}
@-webkit-keyframes treeTableShow {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}
</style>

<style lang="scss" rel="stylesheet/scss" scoped>
$color-blue: #2196f3;
$space-width: 18px;
.ms-tree-space {
  position: relative;
  top: 1px;
  display: inline-block;
  font-style: normal;
  font-weight: 400;
  line-height: 1;
  width: $space-width;
  height: 14px;
  &::before {
    content: "";
  }
}
.processContainer {
  width: 100%;
  height: 100%;
}
table td {
  line-height: 26px;
}

.tree-ctrl {
  position: relative;
  cursor: pointer;
  color: $color-blue;
  margin-left: -$space-width;
}
</style>
